So, again, whenever GPO settings make tweaks to special sections of the registry on a client machine, those settings will self-regulate, that is, reverse themselves—when the GPO no longer applies to that computer. When Group Policy processes, it double-checks four special sections of the registry. When new settings inside these keys appear, the machine knows they need to be put into place immediately. When settings inside these keys disappear (GPO removal), the settings are reversed. Here is a listing of those four registry keys that are being watched by Group Policy:

• HKLMSoftwarePolicies
• HKLMSoftwareMicrosoftWindowsCurrentVersionPolicies
• HKCUSoftwarePolicies
• HKCUSoftwareMicrosoftWindowsCurrentVersionPolicies